Data warehouse for national water quality program with links to chemical, biological, and physical data for water, sediment and animal tissues, nutrient, pesticide, and VOC levels, streamflow, and ground water levels from national study units.

Homepage of the Office of Water Quality programs on the quality of the Nation's surface water and ground water resources, with links to general information, quality assurance, software, data, publications, USGS facilities, techniques, and programs.

Homepage for USGS water quality information. The NWISWeb discrete sample database is a compilation of over 3.5 million historical water quality analyses in the USGS district databases. Also includes access to real-time data and a tutorial.

Multiple studies addressing urban water-quality issues, to describe biological, chemical, and physical characteristics of urban water resources over time, and relate those characteristics to natural processes and human activities

Program to compile data from the National Water-Quality Assessment Program study units to study national trends with links to sediment coring sites, video on Salt Lake City, study units identification, and publications.